Abrasive plumber{3 s tool

ABSTRACT

The invention is concerned with an abrasive plumber&#39;&#39;s tool for precleaning metal surfaces, particularly tubes and fittings, preparatory to soldering. The inventive plumber&#39;&#39;s tool comprises a strap of abrasive material for cleaning the end portions of tubes or pipes and having a cylindrical plug of abrasive material connected to each end for cleaning mating portions of standard fittings, each plug being dimensioned for a different size fitting. Essentially, the plug diameters are designed slightly oversize to insure a uniform abrasive pressure about the interior circumferential area of a fitting and the lengths are designed to insure cleaning of the tube or pipe stop within the fitting. A shoulder is provided extending radially from each plug to fix the extent of insertion within the fitting and to abut and clean the traverse end of the fitting.

United States Patent Dreger [54] ABRASIVE PLUMBERS TOOL Erich A. Dreger, 32 School Lane, Cherry Hill, NJ. 08034 22 Filed: Nov. 29, 1968 21] App1.No.: 779,677

[72] Inventor:

s21 u.s.c1 ....s1/s92 s11 1m.c1...... .3241115/00 [58] Field ofSearch ..s1/1s1,1s0,1s4,3ss,391-393, 5 1/394, 400, 401, 39s; 15/10403, 104.04, 104.05

[56] References Cited UNITED STATES PATENTS 926,524 6/1909 Wattles ..5l/358 1,283,070 l0/l9l8 Callender. ..1s/104.04

Primary Examiner-Othell M. Simpson Attorney-Walter H. Sponagle [57] ABSTRACT The invention is concerned with an abrasive plumber's tool for precleaning metal surfaces, particularly tubes and fittings, preparatory to soldering. The inventive plumbers tool comprises a strap of abrasive material for cleaning the end portions of tubes or pipes and having a cylindrical plug of abrasive material connected to each end for cleaning mating portions of standard fittings, each plug being dimensioned for a different size fitting. Essentially, the plug diameters are designed slightly oversize to insure a uniform abrasive pressure about the interior circumferential area of a fitting and the lengths are designed to insure cleaning of the tube or pipe stop within the fitting. A shoulder is provided extending radially from each plug to fix the extent of insertion within the fitting and to abut 2,802,314 8/1957 Mandzick ..5 1/393 and clean the travel-Se end fth fitti 3,168,799 2/1965 Johnsonm. ...5l/392 3,557,496 1/1971 Martin ..51/391 3 Claims, 6 Drawing Figures PATENTED FEB 1 1972 lib ABRASIVE PLUMBERS TOOL This invention relates to a plumbers tool and, particularly, to a plumbers tool for precleaning metal surfaces preparatory to soldering. More particularly, the invention concerns a plumbers tool adapted to preclean portions of tubes or pipes and mating portions of connectors or fittings which are intended to become parts of soldered joints.

A fundamental operation in the plumbing profession and one calling for no small amount of skill and knowledge is that of soldering. Essentially, this operation may be defined as a joining process wherein metal parts are coalesced by the application of heat thereto using nonferrous filler metals, called solders. The temperatures to which the parts are heated are generally below 800 F. and sufficient to melt the solder which is usually distributed between the properly fitted or mated surfaces of the joint by capillary attraction.

As a general proposition the metals to be joined by a soldering operation dictate the type of flux, solder and heating methods to be employed. Accordingly, it is apparent that many variables affect the actual ease of soldering different metals and classification in this regard is almost impossible. However, there is general consensus that regardless of the metals to be joined or the variables involved, an essential requirement for the obtention of a sound soldered joint is the precleaning of the surfaces intended to become a part of the soldered joint.

The essentiality of the precleaning requirement stems from the very nature of the soldering process, which involves the wetting or alloying of the solder with the base metal. Foreign material which is not wetted or alloyed interferes with the sol dering process by not permitting the solder to flow as a thin film. An unclean surface may result in the formation of small globules of solder, contributing to the formation of a poor joint. Accordingly, various chemical and/or mechanical precleaning techniques have been employed in the prior art to satisfy this requirement.

In the usual household plumbing installation or repair job encountered by plumbers or handymen, it is necessary to join seamless copper water tube to a fitting, such as an el, tee or straight fitting, by the soldering process. Precleaning of the surfaces to be joined has ordinarily been accomplished by tcdiously rubbing such surfaces with an abrasive material, such as emery cloth. In addition to the time-consuming disadvantage of such procedure, there is the added imposition of frequently required examination to insure that the full surface area intended to be joined is adequately cleaned. However, the most important disadvantage resides in the all to frequent occurrence of poorly soldered joints attributed to nonuniform cleaning which do not manifest themselves until tested. Where testing is done intentionally, there is the attendant expense and inconvenience of resoldering the joint. Where testing is the inherent result of subjecting the tubes and fittings to normal operation as in the case of copper water pipes, there may be substantial consequential damage. Nonuniform cleaning may result from the application of more pressure or rubbing in one area than in another or from inadvertently failing to clean a portion of the metal surface forming the soldered joint, an easily overlooked portion being the transverse end of the fitting or the tube or pipe stop therein.

Accordingly, a principal object of the present invention is to provide a plumbers tool for precleaning metal surfaces which will avoid the foregoing disadvantages of the prior art.

Another object of the invention is to provide a plumbers tool for precleaning metal surfaces which is simple and efficient in its operation.

A further object of the invention is to provide a plumbers tool for abrasively precleaning tubular metal surfaces which is adapted to provide full surface contact with the mating portions of tubes and fittings preparatory to soldering.

Other objects of the invention will in part be obvious and in part appear hereinafter in the following description and accompanying drawings wherein FIG. 1 is a plan view of a preferred embodiment of the invention,

FIG. 2 is a view in cross section through 2-2 of FIG. I, FIG. 3 is a side view ofthe embodiment of FIG. I, FIG. 4 is a partial view in cross section through 4-4 of FIG.

1 1 FIG. 5 is a partial view in partial section depicting an end of the embodiment of FIG. I with its plug in operable engagement with a fitting, and

FIG. 6 is a partial view in perspective of the strap portion of the embodiment of FIG. I in operable engagement with the end portion of a tube.

In general, the inventive plumbers tool comprises a short length of an abrasive strap having an abrasive plug mounted at each end.

The strap is primarily designed for precleaning the end portions of metal tubes or pipes preparatory to soldering, which end portions are intended to become parts of the soldered joints, and to afford full surface contact therewith. The length of the strap is sufficient to conveniently wrap around the entire circumference of the tube or pipe, while the thickness is not greater than that necessary to permit a bending radius therefor. The width of the strap is designed at least equal to the length of the portion of the connector or fitting which will be joined to the tube or pipe to form the soldered joint. Precleaning with the strap is effected with a minimum of effort and time by merely wrapping the strap about the tube or pipe with a single turn, and providing the strap with a few quick rotary movements relative to the tube or pipe.

The plugs are employed for precleaning the portions of connectors or fittings which are intended to become part of a soldered joint, each plug being adapted for a different size connector or fitting. A preferred combination of plugs comprises one plug adapted for use with a k-inch fitting and the other plug adapted for use with a 55-inch fitting, these fitting sizes being commonly encountered in the plumbing trade. Each plug comprises a cylindrical holding portion having a neckeddown, cylindrical working portion coaxially extending therefrom, the holding portion forming a shoulder extending radially from the abutting end of the working portion.

The working portion is designed with a diameter which is slightly oversize for the fitting into which it is to be inserted during the precleaning operation. For example, the nominal -inch and ya-inch fittings aforementioned would be precleaned using plugs having working portion diameters of five-eighths of an inch and seven-eighths of an inch, respectively. The length of the working portion is designed to reach the annular pipe stop within the fitting when the end thereof abuts the shoulder provided by the holding portion. Operable engagement with a fitting preparatory to soldering is effected by manually applying a slight pressure to the plug to force the oversize working portion thereof fully into the end of the fitting, whereupon the end of the fitting will abut and press the shoulder of the plug and the remote end of the working portion will contact the pipe stop within the fitting. Precleaning with the plug is then achieved by a few quick rotary movements relative to the fitting.

The holding portion is designed with a diameter slightly larger, e.g., about one-eighth of an inch, than that of the working portion to insure an adequate shoulder for precleaning the end of a fitting and is adapted for seating in the plug-retaining portion of a connecting means.

The connecting means is preferably made of rigid plastic or fiber glass and comprises a plug-retaining portion and a strapretaining portion. The plug-retaining portion is essentially a circular base having the same diameter as the holding portion of the plug and an annular flange or lip about the periphery for centering the plug. A suitable adhesive or glue is employed to permanently bond the plug to the connecting means when the holding portion of the plug is properly seated within the plugretaining portion of the connecting means. Two parallel rectangular flanges are symmetrically affixed to the circular base of the connecting means and extend perpendicularly therefrom in a direction opposite the plug to constitute the strap-retaining portion of the connecting means. The two flanges are spaced apart to permit the end of the strap to be The strap and plugs may be molded from the same material 7 and preferably, comprise a resin matrix which has been.saturated with finely divided aluminum oxide, silicon carbide or other abrasive grains and then cured to promote bonding. While a variety of known resins and abrasive grains may be employed in making the invention, selection should be made on the basis of providing a resultant material which is characterized by a degree of sponginess or flexibility which will permit the slightly oversize plug to be inserted snugly within a corresponding fitting, thereby permitting a uniform abrasive force to be exerted over the full circumferential surface of the intended joint portion of the fitting. The material selected should also be characterized by good wear-resistance to insure substantially original plug dimensions being maintained for a reasonable period of use. Another factor of no less importance in making a proper selection is the abrading properties of the resultant material. Desirably, the material should be capable of fine cleaning without scoring or scratching the metal surface upon which it is used in order to retain the original snug mating of tube and fitting.

For the purpose of providing a better understanding of the invention, reference is now made to the accompanying drawings wherein like reference numerals refer to the same construction elements throughout the several figures.

FIG. 1 provides a plan view of an embodiment of the invention and depicts abrasive strap 10 intermediate a pair of abrasive plugs of different sizes joined at its ends by connecting means. Each of the plugs is coaxially aligned with the longitudinal axis of strap 10 and comprises cylindrical working portions 11 and 12, respectively, extending outwardly from cylindrical holding portions Ila and I2a, respectively (not shown in FIG. 1.), and forming shoulders 11b and 12b, respectively, therewith. The holding portion of the larger plug 11 is seated within and permanently bonded to the cup formed by circular disc 13a and annular flange 13b of the connecting means at one end of strap 10 while the holding portion of the smaller plug I2 is seated within and permanently bonded to the cup formed by circular disc 14a and annular flange 14b of the connecting means at the other end of strap 10. The end portions of strap 10 are permanently bonded to and sandwiched between a pair of parallel rectangular flanges 13 of the connecting means on the one end and a pair of parallel rectangular flanges I4 of the connecting means on the other end, the sandwiching construction being shown more clearly in the side view set forth in FIG. 3.

The cross-sectional construction of an end portion of an embodiment of the inventive tool is depicted with greater clarity in FIG. 2 showing a view through 2-2 of FIG. 1. The connecting means is shown comprising circular disc 14a (shown generally), annular flange 14b (the thickness thereof being that between the two radially outermost circles) and the two parallel rectangular flanges 14, the latter sandwiching the end portion of strap 10. The cross-sectional area of working portion 12 of the smaller plug is shown bounded by the smallest circle while that of shoulder 12b is shown intermediate the smaller circle and the next larger circle.

Another view, slightly enlarged, of the cross-sectional construction of an end portion of the invention is shown in FIG. 4, depicting a view through 44 of FIG. I. The connecting means comprising circular disc 140 with annular flange 14b peripherally extending from one side and a pair of parallel rectangular flanges symmetrically disposed and extending from the other side is shown linking strap 10 to the plug comprising cylindrical holding portion l2a with cylindrical working portion 12 extending coaxially therefrom and forming shoulder 12b therewith.

FIG. 5 depicts an embodiment of the invention in operable engagement with a straight fitting [5 which has previously been joined to a tube 16. As revealed by the partial section view, the working portion ll of the larger plug of FIG. 1 has been fully inserted within fitting l5. thereby causing the remote end of the plug to contact tube stop 15:: and the trans verse end of fitting 15 to contact shoulder llb. The slightly oversize diameter of working portion I1 and the slightly com pressive nature of the abrasive material with which it is formed permits full surface contact with the interior of fitting l5. Accordingly, rotary movement of the plug or fitting relative to each other effects a uniform and complete cleaning of the plug-contacted metal surfaces. The holding portion Ila of the plug is shown permanently bonded and seated within the cup portion of the connecting means comprising annular flange 13b and circular disc [3a with one of the parallel rectangular flanges l3 emanating therefrom.

Use of the invention to perform the cleaning operation for the exterior of the portion of a tube to be inserted within a fitting preparatory to soldering is shown in FIG. 6. Strap I0 is depicted here wrapped about the end portion of tube I6 in operable engagement. In practice, the operator would grasp tube 16 with one hand and press the free ends of strap 10 together with the other hand to maintain substantially complete circumferential contact with tube 16. Thus, relative rotary movement permits rapid and uniform cleaning of the end portion of tube 16.

While the invention has been described and disclosed in connection with various specific embodiments thereof, it is understood that no limitations or restrictions are intended thereby and that said embodiments are merely indicative of the best mode of practicing the invention. It is contemplated that various size plugs other than those specifically described herein may be utilized in the practice of the invention. It is also contemplated that the peripheral edge of the plug working portion may be beveled to more closely accommodate a complementary contoured, fitting tube stop and that the plug shoulder may be beveled to accommodate a chamfered tube end.

Accordingly, the embodiments in which an exclusive property or privilege is claimed are defined as follows in the appended claims.

I claim:

l. A plumbers tool for precleaning the exterior surface of a metallic tube and the interior surface of a sleevelike fitting having an internal annular tube stop intermediate of its ends and adapted to be soldered to said tube slidably received within said fitting, said tool comprising:

abrasive strap means adapted to frictionally engage the exterior surface of said tube; and

abrasive plug means attached to at least one end of said strap means,

said strap means serving as a handle for said plug means,

said plug means comprising a cylindrical holding portion and a cylindrical working portion coaxially extending from an annular shoulder provided by said holding portion, said working portion to be inserted into, and to fri ctionally engage the interior surface of, said fitting,

the diameter of the cylindrical working portion os said plug means being slightly oversize to insure full circumferential surface contact when slidably inserted within said fitting, and

the length of the cylindrical working portion of said plug means being substantially equal to the spacing between the end of said fitting and said tube stop so as to enable the remote end of said plug means working portion to contact the tube stop of said fitting when the transverse end of said fitting abuts said shoulder, thereby to simultaneously clean the transverse end, the internal tube stop and the interior surface of said fitting.

2. A tool according to claim I wherein said strap means and plug comprise a cured material comprising a resin matrix saturated with aluminum oxide.

3. A tool according to claim 2 including plug means of different sizes connected at each end of said strap means, one of said plug means being adapted to clean la-inch nominal size fittings and the other of said plug means being adapted to clean %-inch nominal size fittings. 

1. A plumber''s tool for precleaning the exterior surface of a metallic tube and the interior surface of a sleevelike fitting having an internal annular tube stop intermediate of its ends and adapted to be soldered to said tube slidably received within said fitting, said tool comprising: abrasive strap means adapted to frictionally engage the exterior surface of said tube; and abrasive plug means attached to at least one end of said strap means, said strap means serving as a handle for said plug means, said plug means comprising a cylindrical holding portion and a cylindrical working portion coaxially extending from an annular shoulder provided by said holding portion, said working portion to be inserted into, and to frictionally engage the interior surface of, said fitting, the diameter of the cylindrical working portion os said plug means being slightly oversize to insure full circumferential surface contact when slidably inserted within said fitting, and the length of the cylindrical working portion of said plug means being substantially equal to the spacing between the end of said fitting and said tube stop so as to enable the remote end of said plug means working portion to contact the tube stop of said fitting when the transverse end of said fitting abuts said shoulder, thereby to simultaneously clean the transverse end, the internal tube stop and the interior surface of said fitting.
 2. A tool according to claim 1 wherein said strap means and plug comprise a cured material comprising a resin matrix saturated with aluminum oxide.
 3. A tool according to claim 2 including plug means of different sizes connected at each end of said strap means, one of said plug means being adapted to clean 1/2 -inch nominal size fittings and the other of said plug means being adapted to clean 3/4 -inch nominal size fittings. 